1. Field of the Invention
The present invention relates to an impact absorbing device for a vehicle, and more particularly, to an impact absorbing device for a vehicle in which a crash response length of a crash box extends.
2. Description of Related Art
In general, an impact absorbing device for a vehicle is mounted on a front side and a rear side according to a longitudinal direction of a vehicle so as to contribute to safety of passengers by absorbing impact when a vehicle crashes into a pedestrian, another vehicle, or an object and to simultaneously minimize deformation of a vehicle body.
Referring to FIGS. 1 and 2, an impact absorbing device for a vehicle in the related art includes bumper beams 1 manufactured in a beam shape to be disposed in a front side and a rear side of a vehicle in a traverse direction of the vehicle and crash box units 3 mounted at both side portions of the bumper beam 1 in the traverse direction of the vehicle in a rear side of the bumper beam 1.
The crash box units 3 are mounted to both side portions of the bumper beam 1 through a stay bracket 2 and are directly mounted to side members 4 to be supported.
The side members 4 extend from both left and right sides in the traverse direction of the vehicle in a longitudinal direction of the vehicle to constitute a vehicle body.
The crash box unit 3 includes a crash box 31 generally shaped like a quadrangular block and a mounting bracket 32 for mounting the crash box 31 to the side member 4.
An opening is formed at a rear surface of the bumper beam 1 in the longitudinal direction of the vehicle, and a tip end of the crash box 31 is inserted through the opening to be fixedly mounted to the bumper beam 1 through the stay bracket 2.
A rear end of the crash box 31 is fixedly mounted to the side member 4 through the mounting bracket 32.
A plurality of beads 31a is formed in a longitudinal direction for the crash box 31, thereby enhancing strength of the crash box 31.
A length L between the tip end of the crash box 31 connected to the bumper beam 1 and the rear end connected to the side member 4 is a minimum of 130 mm to 150 mm in order to prevent damage of a head lamp, a hood, a cooling module, or components mounted to a front side of the vehicle body in a front crash of the vehicle.
In the front crash of the vehicle, the bumper beam 1 and the crash box 31 receive impact and absorb crash energy while being deformed to reduce the crash energy. Accordingly, as a length of the crash box 31 is increased, efficiency of crash energy absorption of the crash box 31 is increased.
However, there is an evitable limit in designing the length L of the crash box 31 due to a limitation of a specification or a design of a vehicle.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.